import Vue from 'vue'
import VueRouter from 'vue-router'
import Login from '../components/login.vue'
import Home from '../components/Home.vue'
import Welcome from '../components/Welcome.vue'
import Users from '../components/user/Users.vue'

Vue.use(VueRouter)

const router = new VueRouter({
  routes: [
    { path: '/', redirect: '/login' },
    { path: '/login', component: Login },
    { path: '/home', component: Home,redirect:'/welcome' ,children:[
      {path:'/welcome',component:Welcome},
      {path:'/users',component:Users}
    ]}
  ]
})
//挂载路由导航守卫
router.beforeEach((to,from,next)=>{
  // to 将要访问的路径 from代表从哪个路径跳转而来 next是一个函数 next()直接放行  next('/login')强制跳转
    //如果用户访问的登录页直接放行   判断用户是否访问登录页
    if(to.path === '/login') return next()
    //从sessionStorage中获取到保存的token值 
    const tokenStr = window.sessionStorage.getItem('token')
    //没有token 强制跳转到登录页
    if(!tokenStr) return next('/login')
    next()
})

export default router
